This invention relates generally to swivel wheels for use with recreational or multi-purpose trailers to be towed behind a vehicle, and in particular to a trailer swivel wheel having a gooseneck axle which may be mounted upon the tongue of a trailer frame and pivoted between a raised and lowered position.
The use of single-axle recreational and multi-purpose trailers designed to be towed behind passenger vehicles is quite widespread. Such trailers may carry campers, boats, snow-mobiles, machinery, furniture, building materials, and an almost limitless variety of heavy articles.
These trailers generally have a frame supporting a load carrying bed or platform, and a tongue extending forwardly from the frame toward the vehicle, with a hitch attached to the front end of the tongue and designed to couple the trailer to a hitch ball mounted on the rear of the vehicle.
It is often necessary to uncouple the trailer from the vehicle, and it is frequently desirable to reposition the trailer when it is uncoupled from the vehicle, either to facilitate recoupling the trailer to the vehicle or to make use or storage of the trailer more convenient. Towards this end, many trailers are balanced about their single, rear wheel axles so that a person may manually lift the front of the tongue and turn or move the trailer. If the load on the trailer is too heavy or cannot be balanced, the weight on the tongue may become too great to lift and support comfortably or safely, even with the leverage provided by the tongue.
To remedy this problem, various swivel wheel devices have been designed to support the tongue of the trailer on an extra tire while the trailer is uncoupled from the vehicle. The designs of several of these devices permit some combination of movement of the swivel wheel when the trailer is turned or rolled, and allow the swivel wheel to be removed, retracted, or lifted to a raised position clear of the roadway when the trailer is coupled to the vehicle.
U.S. Pat. No. 2,296,789 shows one such device wherein a wheel, axle, and forks are positioned below the tongue of a trailer behind the hitch, and may be pivoted upwards between and within the Y-shaped yoke of the trailer frame.
This device does not permit the swivel wheel to be raised to a position completely above the tongue of the trailer, and a portion of the swivel mechanism, forks, and wheel must be disposed below the tongue bar at all times. This device also requires a specially designed frame, and as such, it is not suitable for retrofitting or mounting on the majority of existing trailers having straight tongue bars.
U.S. Pat. No. 2,926,930 discloses a swivel wheel which may be rotated around a tongue bar having a generally circular cross section, the wheel being turned and the trailer repositioned using a handle which is attached to a pair of forks straddling the wheel.
This swivel wheel design is again incompatible with many of the existing trailer frames having tongue bars made from square tubular steel, and could not be easily adapted to use with conventional trailers. Additionally, modifying a trailer to incorporate this swivel wheel would require replacing the existing hitch assembly, a costly and inconvenient proposition. Furthermore, the use of the handle suggests that this swivel wheel, due to its size and the minimal castering of the forks, is difficult to turn or adjust when repositioning the loaded trailer.
U.S. Pat. No. 3,348,861 shows a trailer support wheel which used the spare wheel and tire from the trailer, and incorporates a mounting arm which may be pivoted between and locked at a fully raised and a fully lowered position, and intermediate positions therebetween.
This trailer support wheel does not appear to have any capacity to swivel about the mounting arm, and as such would not aid one in turning or repositioning the trailer.
U.S. Pat. No. 3,360,282 discloses a similar trailer tongue support using the spare wheel rim and tire of the trailer, but in this case uses a lever mechanism to pivot the wheel rim and tire between the raised and lowered positions.
This trailer tongue support again does not appear to permit the wheel rim and tire to swivel about the mounting arm, and requires a trailer having a vertical boat anchor support or similar frame member to secure the wheel rim and tire in the lowered position. The long lever arm requires a second locking mechanism on the tongue bar to secure the wheel rim and tire in the raised position, which again cannot be completely raised above the tongue bar without the lever arm extending substantially below the tongue bar and creating a hazard. Additionally, the long lever arm consumes a great deal of space along the tongue bar, and could interfere with the hitch, stabilizer bars, winch, or other features or accessories on the trailer.
U.S. Pat. No. 3,314,692 discloses a retractable trailer tongue jack incorporating a swivel wheel which may be pivoted upward to a raised position.
This retractable jack similarly uses a smaller castered wheel which is pivoted up into a recess in the yoke of the trailer frame, therefore precluding mounting the jack on many existing trailers, or using the spare trailer wheel rim or tire. The wheel and pivot mechanism cannot be raised above the trailer tongue, a feature particularly adopted for use with horse trailers having front doors which require clearance above the trailer tongue.
U.S. Pat. No. 3,655,220 shows a spare wheel carrier for supporting the tongue of a trailer in which the wheel rim and tire are carried in a rack and may be pivoted downward to a lowered position on a hinged mechanism which also permits the wheel rim and tire to swivel.
This spare wheel carrier does not permit the wheel rim and tire to be raised above the trailer tongue, and indeed the wheel rim and tire are disposed completely below the trailer tongue when secured in the carrier rack. Furthermore, the swivel wheel disclosed does not provide a significant castering effect, and again requires the use of a sizable portion of the tongue bar for mounting the carrier rack and the pivotable wheel mount.